Many industrial and agricultural sectors need to use soft water. In textile and dyeing factories, hard water used for washing textiles will cause textile stains, affecting the beauty and strength. Processing food with hard water can cause protein precipitation and make it harder to cook. In winemaking, when the hardness of water exceeds 4 °, the wine will be cloudy and have a bad flavor. Hard water also has an impact on pesticides, it will be generated with the emulsifier precipitation, reduce the effectiveness of the drug, and even produce drug damage.
Hard water also has a greater impact on the boiler. Boiler hard scale, boiler water is not in direct contact with the furnace wall, so that the heat can not be quickly absorbed, the temperature of the furnace wall can reach more than 1000 ℃, the appearance of the formation of easy to fall off the oxide film, serious oxidative corrosion, resulting in the life of the boiler is greatly reduced. In addition, when the scale decomposition, will release a large amount of CO 2, so that the scale local burst off; when the furnace wall at high temperatures, once there is water from the seam infiltration, the wall of the furnace wall cooled by the sudden heat, it is easy to crack. Hard water is also a waste of fuel, when the boiler wall produces 1mm thick scale, it is necessary to consume more coal 3%~5%. In addition, hard water also has an impact on the heat exchanger. In the exchanger piping, hard water will produce scale to impede the flow of water, heat exchange effect is poor and easy to produce corrosion under the scale, pipe perforation, damage, material leakage and other adverse effects.
Hard water has a greater impact on people's health. The Chinese Academy of Preventive Sciences in Xi'an, Shaanxi Province, long-term drinking of mineral water in the population survey, found that they than the nearby living conditions of the average life expectancy of people with similar conditions 3 years higher. But it does not mean that the lower the water hardness is the better, the United States, Canada, the relevant departments of the year-round drinking 5 ° below the soft water of the population survey, found that the cardiovascular mortality rate of up to 10.1% above. Therefore, the relevant aspects of the Canadian regulations: soft water can not be directly for drinking water. According to the relevant information, the best drinking water between 8 ° - 18 °, not more than 25 °. If you drink hard water for a long time, it will lead to an increase in the incidence of kidney stones. Washing and bathing with hard water will form calcium and magnesium soaps, which are sticky like gelatin and stick to the face and skin, making it difficult to get rid of dirt. Dirt is not washed, blocking the opening of the skin glands, the formation of embolism, affecting the normal metabolism, so that the skin premature atrophy aging. Calcium and magnesium ions in high hardness water combined with sulfate will make the water produce a bitter taste, but also make people's gastrointestinal dysfunction, temporary bloating, gas, diarrhea and other phenomena. China's northern region drinking high hardness of groundwater, so long lived in the south of the people first to the north of the beginning of a period of time will appear the so-called "soil and water" phenomenon.
Hard water also has an impact on people's daily lives. Hard water can form calcium fatty acids with detergents, reducing the effectiveness of washing. Long-term use of hard water laundry, clothes become hard, not soft. If you wash your hair with hard water, your hair will not be straight. Use hard water to make tea will reduce the solubility of the active ingredients, so that the tea "color, aroma, taste" change, reduce the pleasure of drinking tea. Hard water cooking fish, meat, vegetables will not be easy to cook and affect the body's absorption of nutrients. Hard water will make the coffee caffeine, tannins released, so that the flavor of coffee greatly reduced. Hard water also reduces the yield of bean curd and impairs the nutrient content. Hard water affects people's daily lives in many ways, and we can't list them all in this article.
Groundwater is the hardest water, and it has a greater impact on our daily lives and industrial production, so it needs to be softened before use. Tap water for hard water; pure water for soft water, also contains calcium and magnesium ions, drinking pure water is not really pure water.
Speaking of so many hard water hazards next we should also understand the softening of hard water. We have learned that the hard water softening method has two categories:
One is the drug softening. Can be utilized in high school textbooks mentioned lime soda method, sodium phosphate method and so on. This type of method can remove calcium and magnesium ions by precipitation. Sulfonated coal can be in the water Ca2+, Mg2+ and Na+ exchange to achieve the purpose of softening; when sulfonated coal after a period of time will lose the ability to soften, it can be placed in 8% ~ 10% of the salt water soak to restore the softening ability. In daily life: when washing face, you can add half a cup of milk or a pinch of salt in the water to remove calcium and magnesium ions to a certain extent.
There are also many devices for softening hard water, and we have seen only three in our survey. The first is a softening machine; there is a resin in its equipment, which is a porous, insoluble exchange material containing millions of tiny plastic balls. When water passes through these balls, calcium and magnesium ions can be removed. The second type is pure water machine; water can get pure water after being processed by multi-media filter, activated carbon fine filter, ultrafiltration membrane, ozone and other processes. The third type is ion exchange equipment; let the water pass through multi-media filter, activated carbon, Yang bed, Yin bed, degassing, fine gas, fine Yang bed, mixed bed, ultraviolet sterilizer, fine filter. Many impurities can be removed from the water. These three kinds of equipment in addition to calcium and magnesium ions used or drug softening method, which are used to ion exchange resin.
The second is the heating method. Boil the water, and cook a little more time, can be converted to calcium and magnesium ions in addition to pot scale, hard water to a certain extent to get softened.
In industrial production, the boiler should be removed if more scale is formed. Remove the method is generally 4% ~ 5% of the mass fraction of hydrochloric acid for pickling, pickling in order to reduce the corrosion of the acid on metal equipment, commonly used Urotropine as a corrosion inhibitor. Boiler descaling can be used special boiler descaling agent such as SAF01-03, KAC01-03 and so on.
Daily life, we also have a simple way to remove the scale. Pour 4% ~ 5% hydrochloric acid in the thermos bottle can be removed from the bottle scale. Kettle descaling methods, we understand the following kinds: ① careful to boil the kettle to just dry, immediately immersed in cool water, the scale will be unevenly heated off. ② in the kettle add vinegar, burned on the fire until warm can also remove the scale. ③ new kettle with half a pot of yams, filled with water to cook, do not rub the inner wall, the future use will not have scale. Old kettle with the above method to do one or two, not only can remove scale, and later boil water will not produce scale. ④ Add a pinch of baking soda in the kettle and boil the water for a few minutes to remove the scale. ⑤ Put some potatoes in the kettle and boil the water for 10 minutes. (6) Boil eggs in the kettle several times. (7) Put a clean mask in the kettle to boil the water, the scale will only be deposited on the mask, and no scale will be formed on the kettle. ⑧ Put a magnet in the kettle to boil water, no scale.